Right now in 5.4 it feels as if, atleast for people like me who are crafting/harvesting, you have nothing to do for the first couple of days when you're waiting for your skills to get high enough so you can do the content you want. And this is with a higher training speed.
My suggestion is a global time back feature. It would work similar to the regular time bank for each category with 2 big diferences.
The first being that the time stored in this time bank can be used for any skills, not limited to the category it is in.
The other is that it can't actually be trained like a normal tree, instead new players would be granted time here so they could get to whatever content they wish to play faster. Maybe not right away, but maybe after a day or something like that.
Increasing the time you get when you start can also work as a catch-up mechanic for new players just getting into the game.
Other uses for the Global Time Bank could be as a compensation to players should something go wrong.
For example, imagine that all servers went down for a whole day and every player lost a days worth of skill training. Sure, ideally you don't want this to happen but it could still happen. By using the Global Time Bank, you could give all the players a days worth of skill training. Sure this would not be as much as the 3 days worth they lost (1 per category, 6 total if they're VIP) but I'm sure most players wouldn't be as angry with you for the servers going down.